Just tested a vet clinic that has welded sheetgoods in there that is shrinking and seams opening up, the installation co said there was a moisture issue when they pulled up the old sheetgoods, said they were going to use some super duper adhesive on it, but did not moisture test supposedly. The floor is sticking but shrinking.

Two of my sensors read HI and one 99% the next day. Just wonding if you think this could be a lack of acclimation or an actual moisture issue. Floor looks a teeny bit bumpy underneath.

Pm me some pics. All cheap vinyl shrink. Seams should not open up if properly heatwelded. Or were they chemical welded?

If the the vinyl shrinks like that it could be an instalation problem. When vinyl has a moisture problem it should bubble and not stick. If seams open it can be a sign of moisture problems coming but usually it is poor woorksmanship.

I guess the super duper adhesive is working. Otherwise it should be blowing off the floor. I got new readings, 2 out of 3 were "Hi", the other was 97% rh. Me thinks they brought it in hot and installed with HVAC going. Still the vet clinic is a crappy layout, coved, so it was not a blow and go install, yes heat welded seams.

If they used some adhesive in antisipation of a moisture problem they would have used. Non water soluble product. It sounds to me like the fix is to properly re heatweld. If you don't have evidence of a moisture problem and the bond of the vinyl to concrete is still good, you are looking at high rh as an undiagnosed symptom.

For example, you go to the doctor and say doc I have a headache, Doc I must have cancer. The headache might be a symptom of cancer but until you get that blood/mri/pet test, the doctor can't say you have cancer, you just have an undiagnosed symptom.

Ea, the seams have been rewelded and the vinyl shrank more and opened up the seams again. No signs of staining, or anything else besides shrinking seams and the hi test numbers. The heat is on now, and the slab temp is almost exactly the ambient temp. Installed in the summer when it was hot and not acclimated, so I am leaning toward that, not the adhesive or moisture.

This is right up Ray's alley, I think he knows for sure but is holding out.

I was discussing this with my dad, two questions:
1. Are the expanding seams uniform or perhaps only in places where the vinyl is exposed to direct sun light?
2. Is there any cracking or discolouration, could be a plasticizer migration problem?